In South Africa, there are a limited number of population estimates of the prevalence of diabetes and its association with psychosocial factors. This study investigates the prevalence of diabetes and its psychosocial correlates in both the general South African population and the Black South African subpopulation using data from the SANHANES-1. Diabetes was defined as a hemoglobin A1c (HbA1c) ≥6.5% or currently on diabetes treatment. Multivariate ordinary least squares and logistic regression models were used to determine factors associated with HbA1c and diabetes, respectively. The prevalence of diabetes was significantly higher among participants who identified as Indian, followed by White and Coloured people, and lowest among Black South Africans. General population models indicated that being Indian, older aged, having a family history of diabetes, and being overweight and obese were associated with HbA1c and diabetes, and crowding was inversely associated with HbA1c and diabetes. HbA1c was inversely associated with being White, having higher education, and residing in areas with higher levels of neighborhood crime and alcohol use. Diabetes was positively associated with psychological distress. The study highlights the importance of addressing the risk factors of psychological distress, as well as traditional risk factors and social determinants of diabetes, in the prevention and control of diabetes at individual and population levels.

Hypertension is the leading cardiovascular disease in Africa. It is increasing in prevalence due partly to the epidemiological transition that African countries, including South Africa, are undergoing. This epidemiological transition is characterised by a nutrition transition andurbanisation; resulting in behavioural, environmental and stress changes that are subject to racial and geographic divides. The South African National Health and Nutrition Examination Survey (SANHANES) examined the association of traditional risk factors; and less traditional risk factors such as race, geographical location, social stressors and psychological distress with hypertension in a national population-based sample of South Africans. Data were analysed on individuals ≥15 years who underwent a physical examination in the SANHANES (n = 7443). Hypertension was defined by blood pressure ≥140/90 mmHg or self-reported hypertension medication usage. Stepwise regression examined the association of demographic, socioeconomic, life stressors, and health risk factors with systolic blood pressure, diastolic blood pressure, and hypertension. Secondly, the risk factor associations and geographical location effects were investigated separately for the African race group. Increasing age (AOR = 1.069, p < 0.001); male gender (AOR = 1.413, p = 0.037); diabetes (AOR = 1.66, p = 0.002); family history of high blood pressure (AOR = 1.721, p < 0.001); and normal weight, overweight and obesity (relative to underweight: AOR = 1.782, p = 0.008; AOR = 2.232, p < 0.001; AOR = 3.874, p < 0.001 respectively) were associated with hypertension. Amongst African participants (n = 5315) age (AOR = 1.068, p < 0.001); male gender (AOR = 1.556, p = 0.001); diabetes (AOR = 1.717, p = 0.002); normal weight, overweight and obesity (relative to underweight: AOR = 1.958, p = 0.006; AOR = 2.118, p = 0.002; AOR = 3.931, p < 0.001); family history of high blood pressure (AOR = 1.485, p = 0.005); and household crowding (AOR = 0.745, p = 0.037) were associated with hypertension. There was a significantly lower prevalence of hypertension in rural informal compared to urban formal settings amongst African participants (AOR = 0.611, p = 0.005). Other social stressors and psychological distress were not significantly associated with hypertension. There was no significant association between social stressors or psychological distress and hypertension. However, the study provides evidence of high-risk groups for whom hypertension screening and management should be prioritised, including older ages, males, people with diabetes or with family history of hypertension, and Africans who live in urban formal localities.

The developmental origins of health and disease (DOHaD) hypothesis states that environmental influences in utero and in early life can determine health and disease in later life through the programming of genes and/or altered gene expression. The DOHaD is likely to have had an effect in South Africa during the fifty years of apartheid; and during the twenty years since the dawn of democracy in 1994. This has profound implications for public health and health promotion policies in South Africa, a country experiencing increased prevalence of noncommunicable diseases (NCDs) and risk factors and behaviours for NCDs due to rapid social and economic transition, and because of the DOHaD. Public health policy and health promotion interventions, such as those introduced by the South African Government over the past 20 years, were designed to improve the health of pregnant women (and their unborn children). They could in addition, through the DOHaD mechanism, reduce NCDs and their risk factors in their offspring in later life. The quality of public health data over the past 40 years in South Africa precludes the possibility of proving the DOHaD hypothesis in that context. Nevertheless, public health and health promotion policies need to be strengthened, if South Africa and other low and middle income countries (LMICs) are to avoid the very high prevalence of NCDs seen in Europe and North America in the 50 years following the Second World War, as a result of socio economic transition and the DOHaD.